Vehicle reel control



May 19, 1953 c. F. BALL ETAL VEHICLE REEL CONTROL 5 Sheets-Sheet 1 iled Feb, 26. 1947b y A mi W Z A,

Patented May 19, 1953 VEHICLE REEL CONTROL Charles F. Ball and Richard T. Hair, Franklin, Pa., assignors to Joy Manufacturing Company, a corporation of Pennsylvania Application February 26, 1947, Serial No. 731,125

19 Claims. 1

Our invention relates to reeling apparatus for self-propelled vehicles, and more particularly to reeling apparatus for mine locomotives or .shuttle cars where the power supply cable must at one moment be wound in to prevent its being run over by the vehicle and damaged, and at another moment be payed out as the vehicle moves in such a manner as to necessitate an increase in the length of the free cable between the vehicle and the point where the cable is attached to a source of current.

In the operation of mine locomotives and shuttle cars, it is common to supply power to the propulsion motors by means of a cable wound on a reel mounted on the vehicle but having a free end, so to speak, adapted to be connected to the track and trolley, or to two trolley wires, or to a gate end box, or to some other available source of current. As the vehicle moves away rectilinearly from the point of cable attachment, cable must be payed out, and as it moves back towards the point of connection the cable must be wound up to prevent its being run over. Moreover, when the vehicle is moving back and forth in opposite directions past the point of connection of the cable, or back and forth past the mouth of a mine passageway down which the cable extends to a point of connection, the cable must be payed out as the vehicle moves away from the point of connection or from the mouth of the passageway, rewound as the vehicle returns towards the point of connection or the mouth of the passageway, again payed out when the vehicle moves, in the opposite direction, away from the point of connection or the mouth of the passageway, and again wound in on its return. Electrically powered reels have been employed for the purpose of winding in and controlling the paying out of the cable, and resistance has been introduced into the reel motor circuit when cable is to be payed out, in order that the torque may be decreased but tension is an appropriate amount be maintained on the cable. With such arrangements, however, the necessity for having current continuously on the reel driving motor is not a desirable thing. Also there has been developed an arrangement utilizing a motor-pump device in driving relation with the reel and with means for automatically reducing the pressure in the line between a supply pump and the motor-pump device during the paying out of cable, such arrangement utilizing a plurality of differently set relief valves and embodying means for selectively having the one or the other relief valve in control of the pressure in said line depending on Ill) whether the cable reel is rotating to effect winding up of the cable or has just ceased to wind up the cable, or is being rotated because cable is being pulled off of it or has just come to rest after such pulling off operation has ceased. The arrangement last mentioned, however, has employed two relief valves and what is, in effect a selector valve in its operation, and our invention is an improvement over the arrangement mentioned in that the use of a single relief valve in place of the three mentioned and an arrangement for simply varying the setting of such single valve makes possible the same essential mode of functioning, so far as results are concerned, as the more complex arrangement described; and it is a primary object of our invention to provide an improved hydraulic reel drive and control system, and more specifically to provide a simplilied and less expensive reel driving and control system similar in general operations to the one described, but using fewer component devices without omission of any of the operating characteristics. Another object of our invention is to provide an improved multiple critical pressure relief valve. Other and further objects will hereinafter more fully appear in the course of this specification and in the appended claims.

In the accompanying drawings, in which three illustrative embodiments of our invention are shown:

Fig. l is a diagrammatic view of an apparatus of the character described and in which one of the illustrative embodiments mentioned is embodied;

Fig. 2 is a sectional view through a plural setting relief valve mechanism and the setting means therefor;

Fig. 3 is a section, taken on the plane of the line 3-3 of Fig. 1, of a friction arrangement which is an element of each of the illustrative embodiments. Fig. 3 is enlarged;

Fig. 4 is a view similar to Fig. 1, and Fig. 5 a sectional view similar to Fig. 2, together showing another illustrative embodiment of our invention;

Fig. 6 is a View similar to Fig. 1, and Fig. 7 is a view similar to Fig. 2, these two views together showing a further illustrative embodiment of our invention.

In each of the illustrative embodiments a cable reel is hydraulically driven in the winding direction, its driving means including a pump for supplying operating fluid to a motor-pump device, which is connected to the reel to drive the latter and which is also so connected to the reel that as the latter is caused to rotate by the pulling of cable oif of it it drives said motor-pump device in such a manner as to cause the same to function as a pump. To limit the pressure imposed on the motor-pump device when the latter is driving the reel but to insure the development of an adequate torque thereby, a relief valve controlled return line is connected between a conduit connecting the pump and the motor-pump device back to a reservoir from which the pump takes the hydraulic fluid which it supplies to the motor-pump device. may assume various forms within the scope of our invention, but in each of the illustrative embodiments of the latter the relief valves are shown with adjustable means for determining the pressures at which they perform their relief functions, and in each embodiment we have shown, though our invention is not limited thereto, friction actuated means controlled by an element which moves continuously while the reel is rotating, for altering in an appropriate manner the relief valve settings. In different illustrative embodiments different arrangements for varying the settings and controlling the loadings of the plural pressure relief valves are disclosed, but these are to be understood as being illustrative only, and the claims define the scope of the invention.

Now referring to the drawings, and first to Figs. 1 to 3 thereof, it will be noted that a reel I I,

suitably supported on the vehicle to whose propulsion means it is to aid in supplying operating medium has wound thereon a flexible power supply element 12, which, while our invention is not limited thereto, may ordinarily be a conductor cable for electric power having a free end adapted to be connected in any suitable manner to a trolley line and track rail, to two trolley lines, to a gate end box, or the like, none of which is or needs to be shown in the drawings; To drive the drum a motor-pump device 13, which may be of any suitable form and which is illustrated as of the intermeshing gear rotor type, is connected as by a chain M to a sprocket l5 connected to the reel to turn, and to turn with, the latter. To drive the motor-pump device in a reel driving direction, hydraulic fluid is adapted to be supplied to the motor-pump device through a conduit l6 supplied from a reservoir 11, and, after doing work in the motor-pump device l3, the hydraulic fluid is adapted to pass to the tank or reservoir II through a conduit l8. From the reservoir I! a pump 19 suitably driven, and normally continuously driven while power (current) is being delivered to the vehicle, is adapted to take fluid from the reservoir I! through a suction line 20 and to deliver it at an appropriate pressure through a conduit 2| and the body 22 of a plural setting relief valve 23 to the conduit l6 leading tothe inlet or supply passage of the motor-pump device l3.

One of the intermeshing' rotors of the motorpump device is supported upon a shaft 26 which projects from the casing of the motor-pump device and which carries a chain sprocket 21 which interengages with the chain l4 and is suitably held, as by the key 28, to the shaft, so that shaft and sprocket turn together. Before going further, it may be noted that the reel II and the shaft 26 both turn clockwise, as viewed in Fig. 1, when cable is being wound in, and supply of hydraulic fluid through the conduit It to the motor-pump device l3 will cause the rotation mentioned when winding in of the cable 42 is possible, as will normally be the case when the vehicle is moving in a direction to introduce slack into the cable.

Such relief valve devices The sprocket 21 has extending from it a boss 30 on which there is mounted a collar or sleeve member 3 I, which is held by a pin and hole connection 32 against rotation relative to the sprocket, and which is thrust outwardly relative to the boss by springs 33 shown as located in recesses 34, 35 in the sprocket and sleeve member 3| respectively. The boss 30 has an outer end 36 of reduced cross section; and an antifriction bearing 31 rotatably supports a support ring 38 of a lever arm 39 on this reduced outer end 36. A split ring and groove arrangement 40 holds the bearing 31 against displacement endwise from the end 36 of the boss 30. A ring of suitable friction material F' is arranged between the parallel surfaces 4| and 42 of the sleeve member 3! and the support ring 38 and may be secured to either one of the same. This slip friction connection between the sprocket and the arm 39 is of course simply illustrative of friction or even other drives which will exert on the lever 39 a predetermined torque, when the sprocket turns in either direction, as long as it is so turned and until indeed the sprocket commences to turn in the other direction. Specifically, this arrangement will, when fluid is supplied by the pump to the motor-pump device I3 and the reel is driven by the motorpump device, cause the lever arm 39 to be moved into the position shown in Figure 1 and to be held in that position with an adequate force while the reel is rotated clockwise and indeed until the reel is caused to turn counter-clockwise by pulling of cable off of it and there is movement of the sprocket 21 in a counter-clockwise direction by the chain M. This will be appreciated if it be borne in mind that if the friction drive will hold the lever 39 over during slipping of the friction drive it will hold it when there is no slip in the drive. A further reason why the lever 39 will require definite actuation in a counter-clock wise direction will shortly be explained. Further,

when the reel, through counter-clockwise rotation causes the sprocket 21 to turn counter-clockwise, the friction clutch or drive will cause the lever 39 to turn counter-clockwise, and will hold it in its extreme permitted counter-clockwise position until the sprocket 21 is again rotated clockwise by fluid delivered by the pump l9. The friction drive will be made of such a torque-transmitting capacity as to perform this function, which is attended, as will soon be noted, by the highest demand for torque-transmission which is imposed upon it.

Now, referring again to the p ural pressure lief valve device 23, it has been indicated that fluid is free to pass through its body 22. It will be noted that the body has a through passage 45 with which the conduits 2| and I6 communicate. that a return conduit 46, leading by way of a part of conduit [8 to the reservoir I1, is adapted to communicate through a passage 41 in a valve seat 48 with the passage 45 when a relief valve 49 carried by the bottom of a piston 50 is unseated. The piston 50 normally maintains the valve 49 seated, since a passage 5| through the the piston normally maintains substantially equal areas onthe top and bottom of the piston under like pressures, and a spring 52 exerts its force in a valve seating direction. If the pressure gets too high in passage 45, however, fluid acting through a passage 53 may unseat a ball type pilot valve 54 and permit access of the fluid above the piston 50 to an escape passage 55, whose flow area is great enough to release pressure fluid from the upper surface of piston 59 faster than it can be delivered through the passage 5I, and accordingly the higher liquid pressure on the lower end of the piston 50 will unseat the relief valve. The pressure at which the valve 49 will be opened will depend on the pressure with which the valve 54 is held seated, and by changing the latter pressure the relief valve can be made to release pressure from the conduits 2|, I6 to the conduit 46 at widely difiering pressures. It is necessary that there be at all times a pressure in the conduit I8 sufficient to start the reel to winding up cable as soon as any winding can take place. Otherwise put, the cable must always be under. at least a certain minimum tension, and the motor-pump device must always be under a certain minimum pressure adequate to cause the reel to turn in a winding in direction just as soon as the. resistance to reel winding-in rotation is sufficiently reduced, as by movement of the vehicle in the proper direction.

It is desirable to have the valve 54 held seated by sufiicient spring pressure to insure a minimum pressure of the order, say, of 100 to 150 p. s. i. butit is desirable, for normal winding in of .the cable, to have a pressure of say 300 p. s. i. or more in the conduit I6. Accordingly, it is necessary to be able to have the valve 54 always pressed in a closing direction by a force which will maintain say 100 to 150 p. s. i. (as may be selected) in line I6 even when the cable is being pulled oif of the reel, as this will enable the motor-pump device to start to act as a motor and shift the position of the lever 39 the instant that the vehicle by its movement starts to introduce slack into the cable.

We illustrate some of the various ways, within the scope of our invention, whereby the valve 54 may be subjected to two widely different seating pressures; in Figs. 1 and 2 showing means whereby an adjustable lower pressure may be applied, and a higher pressure secured by adding directly to the valve an additional predetermined (but acljustably predetermined) seating pressure; and in Figs. 4 and 5 showing an arrangement in'which the spring which applies the pressure to the valve to determine the lower relief limit for the pressure in conduit I6 may be additionally loaded, the initial load and the additional loadings each being adjustable, but predetermined when adjusted. In Figs. 6 and '7 a relief valve, nearly counterbalanced, has the loading pressures directly imposed upon it adjusted, said pressures being predetermined when adjusted. Considering first Fig. 2, it will be noted that the ball valve 54 is subjected to the pressure of a spring 80. I The spring 88 rests at its other end on the cylindrical sleeve portion BI of a member 62. This sleeveportion is suitably packed by a gland 63 having an adjustable follower 84. The member 62 is adjustable relative to the follower 64 by means of an enlarged threaded portion 65 engaged with threads 66 formed in the follower. The member 62 also has a hollow cylindrical portion 61 at its outer end which is surrounded by an internally bored hollow member 68 carrying an adjusting screw 59 in its outer end. A rod I extending through a bore 1| in the cylindrical portion 6| of the member 82 is adapted to be forced into engagement with the ball valve 54 and add an additional seating pressure to the latter by means of a spring I3 which rests at one end against the adjustable follower screw 89 and at its other end engages a collar 14 formed on the rod 18. A stop and pivotproviding element 15 is adapted to be held as at 16 on the member 62 and pivotally supports at 11 a lever 18 which is pivotally connected by pin and slot means I8 to the member 68 and is connected at its lower end by a link 19 to the lever 39. The member I5 carries a stop screw which limits the clockwise movement of the lever I8 in Figs. 1 and 2. It will be evident that the compression of the spring 68 may be changed by adjusting the member 62 relative to the member 64, while the pressure exerted by the spring I3 may be adjusted by changing the position of the follower screw 69 and/or by changing the position;

of the stop screw 80. When the lever I8 is moved counterclockwise, in Figs. 1 and 2, it is intended to remove compression from the spring I3 as will obviously be possible by correctly choosing the spring and properly determining its free length.

When the cable I2 is to be wound in, the arm 39 will be moved clockwise in Fig. 1, if it is not already occupying the limiting position determined by engagement of the arm I8 withthe stop 80. In Fig. 1, the cable I2 is being wound in, and the lever I8, being against the stop 80, is holding the frictionally moved lever 39 against further clockwise movement. It will be noted that the pressure of the spring I3 is being exerted on the valve 54, as well as the pressure of the spring 68. Accordingly, the valve 54 cannot be opened until the desired pressure selected for actuation of the motor-pump device I3 during winding in is exceeded. If the cable is pulled off of the reel the arm 39 will be moved counterclockwise in Fig. 1, moving the arm I8 counterclockwise and removing the compression from the spring I3, thus subjecting the valve 54 only to the pressure of the spring 60, and accordingly, during winding in, the pressure maintained in the line I6 will be only that necessary to maintain the desired ten sion on the cable and to insure the starting of the motor-pump device I3 in a Winding in direction when the tension on the cable is reduced by initiation of movement of the vehicle towards the fixed point to which the cable iyconnected.

The structure of Fig. 5 differs from that of Fig. 2 essentially in that the pressure exerted on the valve 54 through a spring 84 is increased rather than being supplemented, as in structure of Fig. 2, when it is desired to permit relief of fluid to the line 46 only at the highest predetermined pressure. The spring 84 engages a collar 85 on a rod 86. A threaded packing carrying member 81 surrounds the rod and is supported in a portion of the relief valve casing. The rod 86 extends through a tubular member 88 which projects at one end from the support and pivotproviding member 89 carried by the casing of the relief valve. The sleeve 88 passes through an adjustable bushing 90 which constitutes an adjustable follower for a spring 9| surrounding the tubular sleeve 88 and acting on a collar 92 on the latter. The sleeve may also carry a spaced collar if desired. The sleeve 88 carries a suitable adjusting screw 94 adapted to engage the outer end of the rod 86. A lever 95 is pivotally supported at 9B and is connected, similarly to the lever I8, to the lever arm 39. When the lever arm 85 is in the position shown in Figs. 4 and 5, against a stop 98, there is imposed on the spring 84 its maximum compression. When the lever 95 is moved counterclockwise from the position shown in these two figures it exerts a thrust on the collar 92 and forces the latter outwardlyto the right in Fig. 5-and removes the pressure which the spring 9| exerts, through the sleeve 88,

the adjustable follower 94 and the rod 86, on the spring 84; and the spring 84 will have its minimum pressure determined by the distance the lever arm 95 can move counterclockwise before engaging an adjustable stop element I00. To summarize, the spring 84, under the reduced compression thereof which exists when the lever 95 is against adjustable stop I provides by itself the minimum pressure setting for valve 54. When the lever 95 engages the stop 98, the setting of spring 9| determines the maximum load on the valve 54.

In Figs. 6 and '7 a different arrangement is shown; and it will be observed that instead of control of a pilot valve, as it were, for regulating the effective relief pressures, there is direct control of the loading spring for the relief valve per se. In these figures it will be observed the fluid pump device I9 has its discharge line 2| connected to an annular groove I with which, at a diametrically opposite point, a conduit I6 connects and leads to a motor-pump device I3 from whose opposite connection a conduit I8 leads to a reservoir II. A sleeve I06 is fixedly mounted in a bore I01 and against a shoulder I08, said bore formed in and said shoulder formed internally upon a casing I09 of the relief valve mechanism H0. The sleeve I06 is peripherally grooved at III opposite the annular groove I05 and has radial passages I I2 connecting the groove III with an internal bore II3. A valve seat H4 is formed on the end of the sleeve I06. A nearly balanced relief valve element I I5 includes a spool IIB slidable in the bore II3, a reduced stem III, and a valve-forming head I I8 at its other end. A passage I I9 extends from end to end through the relief valve for aiding in the balancing thereof. A spring I furnishes the seating pressures for the relief valve and is received in a chamber I2I from which a connection 46' leads to the return line I8. A spring loading member I has a stem I26 slidably received in an adjustable packing-carrying follower I21 and carries a collar I28 against which the spring I20 rests at one end. Its other end is carried by the head I I8. Adjustment of the follower I21 determines the minimum loading of the spring I20 when the collar I28 engages the end of the follower I2I. The stem I26 has adjustably connected to its end an operating member I30 which is pivotally connected at I3I to a lever I32 connected by a link I33 to a pivot element I34 suitably clamped as by a nut I35 to the casing I09. The lever I32 is connected by a link I36 to an arm 39' corresponding generally to the arm 39 but moving oppositely from that arm by reason of the nature of the fluid connections to the motor-pump device I3. When the lever I32 is swung counterclockwise in Fig. 6, it will swing as far as is permitted before the lock nut I40 associated with the member I30 is stopped by the end of the follower member I21. Thus by adjusting the connection between the member I30 and the stem I26 different additional loading pressures can be imposed on the spring I20, while the minimum loading pressure can be adjusted as previously explained. Thus both the upper and lower limiting pressures for maintaining the valve II5 seated can be varied. When the reel II is winding in the cable I2 the lever I32 is forced to the right in Fig. 6, moving the member I25 to increase the load on the spring I20. When cable is being pulled off2 of the reel the lever I32 is moved to the left until the collar I28 en ages the end of the follower I21 and then the lower loading pressure is imposed on the relief valve. Obviously, when the pressure in chamber I I3 gets high enough to move the valve element II5 to the left, by virtue of its action on the annulus of excess area on the valve head II8, there will be a release of liquid to line 46'.

It is unnecessary to extend the description of this invention because the mode of operation of each of the embodiments will be clear from what has already been said. In each of the embodiments, when the cable is being wound in the excess fluid relief mechanism will be subjected to a higher load, and when cable is being drawn off of the reel the load on this relief device will be reduced. In the first embodiment the change in the relief pressures will be effected by changes in the loading of a pilot valve, and when a higher relief pressure is desired there will be exerted on the pilot valve the complemental pressure of a second spring augmenting the force exerted by a constantly acting spring which determines the pressure at which release of excess fluid occurs during the unwinding of cable. In the second embodiment the spring 9| is permitted to increase the compression of the constantly acting spring 84 and thus to increase the seating force exerted on the pilot valve 54 during winding in operation. In the third illustrative embodiment of the invention a spring is caused to exert a relatively low and a relatively high pressure directly on the fluid relief valve, and the change in the pressure exerted on the relief valve is effected by changing the position of a follower member engaged by the spring when the winding in operation is changed to paying out operation and vice versa. In all of the embodiments it will be obvious that there is a simplification as compared with prior devices in that only a single release valve is employed and only a single release connection leading back to the reservoir.

While there are in this application specifically described three forms which the invention may assume'in practice, it will be understood that these forms of the same are shown for purposes of illustration and that the invention may be further modified and embodied in various other forms without departing from its spirit or the scope of the appended claims.

What We claim as new and desire to secure by Letters Patent is:

1. In combination, a vehicle supported cable reel having a conductor cable wound thereon and having a motor-pump device connected in driving relation to it, a pump for supplying operating fluid for said motor-pump device, a reservoir, conduits respectively constituting an intake line for the pump from the reservoir, a continuously open operating fluid delivery line connecting the pump and the motor-pump device, and an alternatively intake and discharge line between the reservoir and the motor-pump device, and means for permitting the escape of fluid from said continuously open operating fluid line at different predetermined pressures, having a single connection with said operating fluid line, a single connection with the reservoir and a single conduit between said connections having a single relief valve therein controlling the escape of fluid at each of said different pressures.

2. In combination, a vehicle supported cable reel having a conductor cable wound thereon and having a motor-pump device connected in driving relation to it, a pump for supplying operating flu d for said motor-pump device, a reservoir, conduits respectively constituting an intake line for the pump from the reservoir, an operating fluid .9 delivery line between the pump and. the motorpump device, and an alternatively intake and discharge line between the reservoir and the motorpump device, and means for permitting the escape of fluid from said operating fluid line at different predetermined pressures, including a single relief valve and means for rendering the same operative to effect relief at different predetermined pressures, said relief valve having a single connection with the reservoir.

3. In combination, a vehicle supported cable reel having a conductor cable wound thereon and having a motor-pump device connected in driving relation to it, a pump for supplying operating fluid for said motor-pump device, alireservoir, conduits respectively constituting an intake line for the pump from the reservoir, annoperating fluid delivery line between the pump and. the motor-pump device, and an alternatively intake and discharge line between the reservoir and the motor-pump device, and means for permitting the escape of fluid from said operating fluid line at different predetermined pressures, including a single relief valve and means for rendering the same operative at different predetermined pressures including means for exerting on said relief valve two substantially different pressures opposing relief-effecting movement thereof, depending on the direction of reel rotation.

4. In combination, a vehicle supported cable reel having a conductor cable wound thereon and having a motor-pump device connected in driving relation to it, a pump for supplying operating fluid for said motor-pump device, a reservoir, conduits respectively constituting an intake line for the pump from the reservoir, anoperating fluid delivery line between the pump and the motor-pump device, and an alternatively intake and discharge line between the reservoir and the motor-pump device, and means for permitting the escape of fluid from said operating fluid line at different predetermined pressures, including a single relief valve and means for rendering the same operative at different predetere mined pressures including a pilot valve controlling its operation and means for exerting on said pilot valve different pressures depending on the direction of reel rotation. I v

5. In combination, a vehicle supported cable reel having a conductor cable wound thereon and having a motor-pump device connected in driving relation to it, a pump for supplying operating fluid for said motor-pump device, a reservoir, conduits respectively constituting an intake line for the pump from the reservoir, an operating fluid delivery line between the pump and the motor-pump device, and an alternatively intake and discharge line between the reservoir and the motor-pump device, and means for permitting the escape of fluid from said operating fluid line at different predetermined pressures, including a single relief valve and means for rendering the same operative at different predetermined pressures including a pilot valve controlling its operation and means for exerting on said pilot valve the pressure of a single spring or the cumulative pressure of two springs depending on the direction of reel rotation.

6. In combination, a vehicle supported cable reel having a conductor cable wound thereon and having a motor-pump device connected in driving relation to it, a pump for supplying operating fluid for said motor-pump device, a reservoir, conduits respectively constituting an intake line for the pump from thereservoir, an operating fluid delivery line between the pump and the motor-pump device, and an alternatively intake and discharge line between the reservoir and the motor-pump device, and means for permit.- ting the escape of fluid from said operating fluid line at different predetermined pressures, including a single relief valve and means for rendering the same operative atv different predetermined pressures including a pilot valve controlling its operation and means for exerting on said pilot valve the pressure of one spring or the pressure of a second spring acting through the first depending on the direction of reel rotation.

7. In combination, a winding reel adapted to have a power conductor wound thereon and to wind in the conductor or to have the conductor drawn off therefrom, a reservoir for a hydraulic fluid, a pump having driving means, a .motorpump device, a driving connection between the motor-pump device and the reel, a connection betweenthe pump and the motor-pump device, a connection between the motor-pump device and the reservoir, means for releasing fluid from the connection between the pump and the motorpump device to the reservoir at relatively high pressure and at a relatively lower pressure including a relief valve responsive to the pressure in such connection and which is openable to release fluid at each of said different pressures,

and means including an element rotated with said motor-pump device for determining the pressure at which said relief valve shall release fluid. 8. In combination, a winding reel adapted to have a power conductor wound thereon and to wind in the conductor or to have the conductor drawn off therefrom, a reservoir for a hydraulic fluid, a pump having driving means, a motorpumpdevice, a driving connection between the motor-pump device and the reel, a connection between the pump and the motor-pump device, a connection between the motor-pump device and the reservoir, means for releasing fluid from the connection between the pump and the motorpump device to the reservoir at relatively high pressure and at a relatively lower pressure including a relief valve responsive to the pressure in such connection and which is openable, to release fluid at each of said different'pressures, and means including an operating'element, an element rotated with said-motor-pump device and a frictional connection between-said elements for determining the pressure at which said relief valve shall release fluid.

9. In combination, a winding'reel adapted to have a power conductor wound thereon and to wind in the conductor or to have the conductor drawn off therefrom, a reservoir for a hydraulic fluid, a pump having driving means, a motorpump device, a driving connection between the motor-pump device and the reel, a connection between the pumpand the motor-pump device, a connection between the motor-pump device and the reservoir, means for releasing fluid from the connection between the pump and the motorpump device to the reservoir at relatively high pressure and at a relatively lower pressure includinga relief valve responsive to the pressure in such connection and which is openable to release fluid at each of said different pressures, and means including an operating element, an elementrotated with the reel, and means for causing said last mentioned element to exert a drag on said operating element for determining the pressure at which said relief valve shall release fluid. r

10. In combination, a winding reel adapted to have a power conductor wound thereon and to wind in the conductor or to have the conductor drawn off therefrom, a reservoir for a hydraulic fluid, a pump having driving means, a motorpump device, a driving connection between the motor-pump device and the reel, a connection between the reservoir and the pump, a connection between the pump and the motor-pump device, a connection between the motor-pump device and the reservoir, unitary means, including but a single relief valve responsive, dependent upon the setting thereof, to such diiferent pres sures, for releasing fluid from the connection between the pump and the motor-pump device to the reservoir at a relatively high pressure and at a relatively lower pressure, and means for determining whether release shall occur at said relatively high pressure or at said relatively lower pressure operatively connected to said reel and having between the same and said reel a slip friction clutch.

11. In combination, a winding reel adapted to have a cable wound thereon and to wind in the cable or to have the cable drawn off therefrom, a reservoir for a hydraulic fluid, a pump having driving means, a motor-pump device, a driving connection between the motor-pump device and the reel, a connection between the reservoir and the pump, a connection between the pump and the motor-pump device, a connection between the motor-pump device and the reservoir, unitary means for releasing fluid from the connection between the pump and the motor-pump device to the reservoir at a relatively high pressure and at a relatively lower pressure, and means for precluding release at the relatively lower pressure while the motor-pump device is operating as a motor including a loading spring, and means for loading the same operated by a drag provided when said reel is rotating in a winding in direction.

12. In combination, a winding reel adapted to have a cable wound thereon and to wind in the cable or to have the cable drawn off therefrom, a reservoir for a hydraulic fluid, a pump having driving means, a motor-pump device, a driving connection between the motor-pump device and the reel, a connection between the reservoir and the pump, a connection between the pump and the motor-pump device, a connection between the motor-pump device and the reservoir, means for releasing fluid from the connection between the pump and the motor-pump device to the reservoir at a relatively high pressure and at a relatively lower pressure, and means for precluding release at the relatively lower pressure while the motor-pump device is operating as a motor including a preloaded loading spring, and means for eifecting the application of the force of said spring when the reel is operated in a winding in direction.

13. In combination, a cable winding reel, 2. motor for driving said reel to wind in cable and driven backwards by said reel when cable is pulled off of the latter, power supply means for said motor, and means for increasing the torque exerted by said motor when driving said reel in a winding direction and for reducing the torque exerted by said motor when it is driven backwards including a spring load controlling element movable to different positions to effect such changes in torque, and means having a slip friction connection with said motor for moving said element to different positions as said motor turns in opposite directions.

14. In combination, a winding reel adapted to have a cable wound thereon and to wind in the cable or to have the cable drawn off therefrom. a reservoir for a hydraulic fluid, a pump having driving means, a motor-pump device, a driving connection between the motor-pump device and the reel, a connection between the reservoir and the pump, a connection between the pump and the motor-pump device, a connection between the motor-pump device and the reservoir, means for releasing fluid from the connection between the pump and the motor-pump device to the reservoir at a relatively high pressure and at a relatively lower pressure including a valve and means for exerting on it different seating pressures, and means governed by the direction of reel rotation and including a slip friction clutch having a driving element rotated with said reel and a driven element, and means moved by said driven element for determining the valve seating pressure.

15. In a cable reeling mechanism, a cable reel, a fluid motor for driving said reel only in cable winding direction, said reel as it is rotated in unwinding direction effecting drive of said motor backwards so that the latter acts as a pump, and control means including a single control valve having different predetermined load-settings and automatically responsive to reel rotation in one direction to effect one control of said motor and to reel rotation in the opposite direction to effect a different control of said motor, whereby diiferent motor torques are provided.

16. In a cable reeling mechanism, a cable reel, a motor connected with said reel for dIiViIlg said reel in cable winding direction and for drive backwards by said reel when the latter is rotated in a cable unwinding direction, and having a connection with a source of operating medium whether driving said reel or driven backwards by it, whereby said motor exerts a torque at both times, and means for controlling the torque exerted by said motor at both times, to cause the motor to exert a higher torque when driving the reel than when driven backwards by the reel, said control means including a control element having a closed position and movable only unidirectionally in transit from closed to open position and having associated therewith means for effecting the exertion in a closing direction upon said control element of one predetermined force when said motor is driving said reel and of a different predetermined force when said reel is driving said motor, said last mentioned means including an element controlled by the direction of reel rotation and movable between difierent predetermined positions to control the force exerted by said last mentioned means in a closing direction upon said control element.

1'7. In a cable reeling mechanism, a cable reel, a motor connected with said reel for driving said reel in cable winding direction and for drive backwards by said reel when the latter is rotated in a cable unwinding direction, and having a connection with a source of operating medium whether driving said reel or driven backwards by it, whereby said motor exerts a torque at both times in a cable winding direction, and means for controlling the torque exerted by said motor at both times, to cause the motor to exert a higher torque when driving the reel than when driven backwards by the reel, said control means including a control element having a closed position and subjected in an opening direction to a force provided by the operating medium and movable only unidirectionally from closed to open position and having associated therewith means for elfecting the exertion in a closing direction upon said control element of one predetermined force when said motor is driving said reel and of a different predetermined force when said reel is driving said motor, said last mentioned means including an element controlled by the direction of reel rotation and movable between different predetermined positions as the direction of reel rotation changes and a spring disposed to exert a force in a closing direction on said control element and to have its stressing predeterminedly altered by the movements between different predetermined positions of said last recited element.

18. In a cable reeling mechanism, a cable reel, a motor connected with said reel for driving said reel in cable winding direction and for drive backwards by said reel when the latter is rotated in a cable unwinding direction, and having a connection with a source of operating medium whether driving said reel or driven backwards by it, whereby said motor exerts a torque at both times in a cable winding direction, and means for controlling the torque exerted by said motor at both times, to cause the motor to exert a higher torque when driving the reel than when driven backwards by the reel, said control means including a control element having a limit position and movable only unidirectionally away therefrom and having associated therewith means including another element controlled by the direction of reel rotation and movable between different predetermined positions to control the force exerted upon said control element by said last mentioned means in a direction towards said limit position, for efiecting the exertion in said last mentioned direction upon said control element of one predetermined force when said motor is driving said reel and of a different predetermined force when said reel is driving said motor.

19. In a cable reeling mechanism, a cable reel, a motor for driving said reel in cable Winding direction only, said reel as it is rotating in unwinding direction efiecting drive of said motor backwards, means energizing said motor irrespective of its direction of rotation whereby it exerts a torque on said reel in cable winding direction, whether or not cable is being wound in or drawn off of said reel, and control means for regulating such torque to cause the same to be higher when said motor is driving said reel and lower when said reel is effecting drive of said motor, including a control element, means for moving the same in one direction when said motor is driving said reel and in the other direction when said reel is driving the motor, an element movable to vary said torque, and loading means controlled by said control element for imposing difierent predetermined loads on said last mentioned element each biasing it in the same direction.

CHARLES F. BALL. RICHARD T. HAIR.

References Cited in the file of this patent UNITED STATES PATENTS Number Name Date 1,683,927 Smith Sept. 11, 1928 7 1,937,077 West Nov. 28, 1933 2,090,707 Sloane Aug. 24, 1937 2,164,600 Tyler July 4, 1939 2,367,106 Doloh Jan. 9, 1945 2,395,302 Slomer Feb. 19, 1946 

